Inlaying continuous filamentous reinforcement in a nonwoven web

ABSTRACT

Inlaying a continuous filamentous reinforcement, such as individual filaments or scrim, in nonwoven web material is effected by carrying the filamentous reinforcement in the slurry stream in a headbox to a web forming porous traveling surface and on the forming surface forming the slurry into a fibrous web with the filamentous reinforcement integrally embedded in the web. Introduction of the filamentous reinforcement into the slurry in the headbox may be effected through one or more nozzles discharging downstream in the headbox, the filamentous reinforcement being transported through the nozzle in a carrier liquid such as water. The nozzle may have a venturi geometry whereby to assure a pressure drop for positively drawing the filamentous reinforcement from the nozzle into the pressurized slurry stream.

United States Patent 11 1 Skaugen INLAYING CONTINUOUS FILAMENTOUSREINFORCEMENT IN A NONWOVEN WEB [75] Inventor: Borgeir Skaugen, Beloit,Wis.

[73] Assignee: Beloit Corporation, Beloit, Wis.

[22] Filed: Dec. 5, 1973 211 Appl. No.'. 421,990

OII' 'IIIIlI/IIIIIIIIII IIIIIIIIIIII' I 1 51 July 1, 1975 PrimaryExaminerS. Leon Bashore Assistant Examiner-Richard V. Fisher Attorney,Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara &Simpson [57] ABSTRACT lnlaying a continuous filamentous reinforcement,such as individual filaments or scrim, in nonwoven web material iseffected by carrying the filamentous reinforcement in the slurry streamin a headbox to a web forming porous traveling surface and on theforming sur' face forming the slurry into a fibrous web with thefilamentous reinforcement integrally embedded in the web.

Introduction of the filamentous reinforcement into the slurry in theheadbox may be effected through one or more nozzles dischargingdownstream in the headbox, the filamentous reinforcement beingtransported through the nozzle in a carrier liquid such as water. Thenozzle may have a venturi geometry whereby to assure a pressure drop forpositively drawing the filamentous reinforcement from the nozzle intothe pressurized slurry stream.

19 Claims, 4 Drawing Figures INLAYING CONTINUOUS FILAMENTOUSREINFORCEMENT IN A NONWOVEN WEB This invention relates to the art ofreinforcing nonwoven webs, and is more particularly concerned withinlaying a continuous filamentous reinforcement in such webs.

lnlaying of filamentous reinforcement in the form of individual fibersor as scrim in nonwoven web material such as paper has heretoforegenerally been effected by lamination, that is, two sheets of desiredcharacteristics have been laminated with the reinforcement therebetweenwhere a reinforcing inlay has been deemed necessary to attain properstrength. This means that the web muust be made on one machine or atleast one operating apparatus of a machine and then the laminating iseffected away from that particular machine or apparatus portion of amachine. Therefore, prior methods and apparatus have been fairlycomplex, expensive, cumbersome, of limited application and relativelyinefficient.

An important object of the present invention is to overcome theforegoing and other disadvantages, deficiencies, inefficiencies,shortcomings and problems in prior methods and structures and to attainimportant new and improved results and advantages in the inlay ing ofcontinuous filamentous reinforcement in nonwoven web materials.

Another object of the invention is to provide a new and improved methodof and means for high speed production inlaying of filamentousreinforcement in nonwoven webs.

A further object of the invention is to provide a new and improvedmethod of and means for inlaying filamentous reinforcement in nonwovenwebs continuously as an integral part of the web-manufacturing process.

Still another object of the invention is to provide a new and improvedmethod of and means for integrally incorporating filamentousreinforcement of diverse selected types, individual filament or scrim,in nonwoven webs coincident with formation of the webs.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof, taken in conjunction with the accompanying drawing althoughvaiations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

FIG. I is a schematic illustration of a web forming apparatus embodyingfeatures of and especially adapted for practice of the presentinvention;

FIG. 2 is a fragmentary sectional elevational view taken substantiallyalong the line "-11 of FIG. 1;

FIG. 3 is an enlarged sectional detail view taken substantially alongthe line III-III of FIG. 2; and

FIG. 4 is a sectional elevational view similar to FIG. 2 but showing amodification.

By way of a practical example, a continuous high speed web formingapparatus as shown in FIG. 1 includes a pressurized fibrous stock supplyinlet 5 leading to a pressure head box 7 extending in an upwardlyinclined direction toward a web-forming porous traveling surface such asa fourdrinier wire belt 8 which extends in an upwardly inclineddirection in its forming run with its inclined direction being providedto accomodate the upward inclination of the headbox. The forming belt 8is driven at a suitable speed in the forming direction as indicated byarrows and is supported on suitable rolls including a breast roll 9 anda couch roll 10 and in the vicinity of the couch roll may have suitablemeans (not shown) for taking offthe formed nonwoven web for furtherprocessing including drying and calendering. At its downstream orforming end the headbox has a slice 11 where the stream of stock isdriven against the forming belt 8 which in this forming area hasassociated therewith drainage and suction means comprising an underlyingperforated plate 12 on top of a suction box having a suction pump 13connected thereto and leading at its lower end to a water collectioncontainer 14.

According to the present invention, inlaying of continuous filamentousreinforcement 15 in a nonwoven web 17 produced by means of the describedapparatus is accomplished by feeding the filamentous reinforcement intothe fibrous stock slurry stream in the headbox 7, and carrying thereinforcement 15 in the slurry in the stream to the forming surface 8where the reinforcement is integrally embedded in the fibrous web formedfrom the slurry. In one form, the filamentous reinforcement 15 comprisesindividual filaments, either monofilament or multifiber or twisted fibertypes and of any suitable gauge and material adequate for the particularcharacter and finish of the web 17 which may comprise paper, roofingfelt, nonwoven fabric, and the like. To this end, the filaments 15 arefed by ejecting each of them through an elongated orifice 18conveniently extending through a manifold I9 located across the upstreamend portion of the headbox 7 and forwardly or in downstream alignmentwith a header 20 with which the inlet 5 communicates. In the illustratedinstance the manifold 19 is provided with a plurality of the orifices 18in spaced parallel relation to supply a desired number of thereinforcing filaments 15 into the slurry stream. For example, theorifices may be in staggered relation in a plurality of rows across thewidth of the manifold. Each of the orifices 18 is dimensioned to providea substantial cross sectional flow area therethrough and to developetherein a substantial velocity of the slurry under pressure from theheader 20 with the pressure drop into the main chamber of the headbox 7.This velocity of the slurry through the orifices l8 assures properdistribution of the filaments 15 submerged in the on-flowing slurrystream.

Delivery of the filamentous reinforcement filaments 15 into the orifices18 is facilitated by conveying the filaments in a liquid carrier throughrespective conveyor and distributor pipes 21 which extend concentricallythrough and into the upstream end portions of the respective orifices 18and terminate in respective discharge nozzles 22 of a preferablygenerally venturi geometry and located intermediate the ends of theorifices, such as about midway between such ends. Thereby the nozzles 22discharge into the stream of slurry rushing through the respectiveorifice 18 with the respective reinforcing filament l5 ejected centrallyof the orifice passage into the stream. Efficiency of ejection of thefilaments 15 into the orifice stream is improved by having the diameterof the upstream portions of the orifices 18 about the delivery pipes 21of smaller diameter than the downstream portions of the orifices andwith the discharge nozzles 22 located at the juncture of thedifferential diameter portions of the orifices substantially as shown inFIG. 3.

Fluid carrier such as water is supplied to the conveyor pipes 21preferably together with the filamentous reinforcement strands orfilaments 15. For this purpose, the entry ends of the pipes 21 may, asshown in FIG. 1, be directed upwardly to receive the filaments 15 fromsuitable supply sources such as spools, reels, spinner heads, extruders,or the like. Communicating with the entry ends of the pipes are suitablemeans for supplying the liquid carrier such as water, herein shown ascomprising a tank 23 with which the entry ends of the pipes communicateand to which a constant head of water is supplied as through a supplypipe 24 under the control of a float operated valve 25. This arrangementhas the advantage of simplicity in supplying the liquid carrier to theconveyor pipes 21 with the filaments l5 and of providing a constantpressure head to induce flow of the carrier fluid on through the pipesand the discharge nozzles 22, the system substantially correlating speedof movement of the filaments with the speed of movement of the slurrystream for efficient operation.

Where a filamentous reinforcement in the form of scrim 27 (FIG. 4) is tobe inlaid continuously in the nonwoven web, the manner of feeding thescrim into the slurry stream may be substantially the same as describedfor feeding the filament type of reinforcement, except that the deliverynozzle arrangement must be modified to accomodate the loosely wovenmaterial comprising the scrim. For this purpose, a scrim delivery nozzle22' of suitable width to accomodate the scrim delivers the scrim into acomplementary orifice 18' in the manifold 19' mounted in the upstreamportion of the headbox 7'. Other features of the system may correspondto those described in connection with FIG. 1.

it will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

I claim as my invention: 1. A method of inlaying a continuousfilamentous reinforcement in a nonwoven web, comprising:

supplying fibrous stock slurry through an elongated orifice into astream traveling through a headbox to a web-forming porous travelingsurface;

feeding filamentous reinforcement through a nozzle dischargingdownstream within the orifice and thereby into the slurry stream;

carrying the filamentous reinforcement in the slurry stream to theforming surface; and

on the forming surface forming the slurry into a web with thefilamentous reinforcement integrally embedded in the web.

2. A method according to claim 1, including effecting a pressure drop atthe discharge end of the nozzle within the elongated orifice.

3. A method according to claim 1, comprising conveying the filamentousreinforcement in a fluid carrier to and through the nozzle into theorifice.

4. A method according to claim 3, comprising supplying the filamentousreinforcement and the fluid carrier into conveyor pipe means leading tothe nozzle.

5. A method according to claim 1, comprising carrying said filamentousreinforcement in a fluid carrier under pressure into the nozzle forfeeding the rein forcement into the slurry stream through the orifice.

6. A method according to claim 1, comprising correlating the velocity offilamentous reinforcement feed ing in the nozzle with the rate of travelof the slurry stream to the web forming surface.

7. A method according to claim 1, comprising feeding the filamentousreinforcement in the form of a plurality of individual filaments throughrespective nozzles into respective orifices discharging into the slurrystream.

8. A method according to claim 1, comprising feeding the filamentousreinforcement in the form of scrim through a nozzle which is ofsubstantial width into an orifice of complementary width and therefrominto the slurry stream.

9. A method according to claim 1, comprisng supplying the fibrous stockslurry into a header, conducting the slurry from the header through saidorifice in a manifold in the headbox, and effecting said feeding of thefilamentous reinforcement through said header and then into the nozzle.

10. Apparatus including a headbox, means for sup plying fibrous stockslurry to flow in a stream through the headbox, and a web-forming poroustraveling surface receiving the slurry from the headbox, the improvementcomprising:

said means for supplying the stock slurry comprising an elongatedorifice discharging into the headbox; and

means for feeding filamentous reinforcement comprising a nozzledischarging downstream within said orifice and thereby into the slurrystream so that the reinforcement will be carried in the slurry stream tothe forming surface and the filamentous reinforcement will be integrallyimbedded in the web.

11. Apparatus according to claim 10, including conveyor pipe meansleading to the nozzle, and means for supplying a fluid carrier to thepipe together with the filamentous reinforcement.

12. Apparatus according to claim 10, wherein said feeding means nozzlecomprises a venturi nozzlev 13. Apparatus according to claim 10, whereinsaid feeding means comprise a plurality of nozzles spaced laterally fromone another and discharging into respective orifices discharging intosaid slurry stream at a plurality of points to feed individual filamentsinto the stream.

14. Apparatus according to claim 10, wherein said feeding means comprisea wide nozzle discharging into a complementary wide orifice to feed thefilamentous reinforcement in the form of scrim into the stream.

15. Apparatus according to claim 10, including a header, means forsupplying the fibrous stock slurry to the header, a manifold forreceiving the slurry from the header and having said orifice providing apassage therethrough into the headbox, said nozzle being directed tofeed the filamentous reinforcement into said passage intermediate thelength of the orifice.

16. Apparatus according to claim 10, wherein the nozzle means isarranged to convey filamentous reinforcement and a fluid carrier intothe orifice.

17. Apparatus according to claim 16, wherein said nozzle means hasventuri geometry.

18. Apparatus according to claim 17, including a header having saidorifice providing an elongated passage therein, said nozzle meansdischarging into said orifice means intermediate the length of saidpassage,

19. Apparatus according to claim 18, including conveyor pipe means indelivering relation to said nozzle means, a carrier fluid tankcommunicating with the pipe means and through which the filamentousreinforcement is supplied into the pipe means, and means for supplyingcarrier fluid to the tankv

1. A METHOD OF INLAYING A CONTINUOUS FILAMENTOUS REINFORCEMENT IN ANONWOVEN WEB, COMPRISING: SUPPLYING FIBROUS STOCK SLURRY THROUGH ANELONGATED ORIFICE INTO A STREAM TRAVELING THROUGH A HEADBOX TO AWEB-FORMING POROUS TRAVELING SURFACE, FEEDING FILAMENTOUS REINFORCEMENTTHROUGH A NOZZLE DISCHARGING DOWNSTREAM WITHIN THE ORIFICE AND THEREBYINTO THE SLURRY STREAM, CARRYING THE FILAMENTOUS REINFORCEMENT IN THESLURRY STREAM TO THE FORMING SURFACE, AND ON THE FORMING SURFACE FORMINGTHE SLURRY INTO A WEB WITH THE FILAMENTOUS REINFORCEMENT INTEGRALLYEMBEDDED IN THE WEB.
 2. A method according to claim 1, includingeffecting a pressure drop at the discharge end of the nozzle within theelongated orifice.
 3. A method according to claim 1, comprisingconveying the filamentous reinforcement in a fluid carrier to andthrough the nozzle into the orifice.
 4. A method according to claim 3,comprising supplying the filamentous reinforcement and the fluid carrierinto conveyor pipe means leading to the nozzle.
 5. A method according toclaim 1, comprising carrying said filamentous reinforcement in a fluidcarrier under pressure into the nozzle for feeding the reinforcementinto the slurry stream through the orifice.
 6. A method according toclaim 1, comprising correlating the velocity of filamentousreinforcement feeding in the nozzle with the rate of travel of theslurry stream to the web forming surface.
 7. A method according to claim1, comprising feeding the filamentous reinforcement in the form of aplurality of individual filaments through respective nozzles intorespective orifices discharging into the slurry stream.
 8. A methodaccording to claim 1, comprising feeding the filamentous reinforcementin the Form of scrim through a nozzle which is of substantial width intoan orifice of complementary width and therefrom into the slurry stream.9. A method according to claim 1, comprisng supplying the fibrous stockslurry into a header, conducting the slurry from the header through saidorifice in a manifold in the headbox, and effecting said feeding of thefilamentous reinforcement through said header and then into the nozzle.10. Apparatus including a headbox, means for supplying fibrous stockslurry to flow in a stream through the headbox, and a web-forming poroustraveling surface receiving the slurry from the headbox, the improvementcomprising: said means for supplying the stock slurry comprising anelongated orifice discharging into the headbox; and means for feedingfilamentous reinforcement comprising a nozzle discharging downstreamwithin said orifice and thereby into the slurry stream so that thereinforcement will be carried in the slurry stream to the formingsurface and the filamentous reinforcement will be integrally imbedded inthe web.
 11. Apparatus according to claim 10, including conveyor pipemeans leading to the nozzle, and means for supplying a fluid carrier tothe pipe together with the filamentous reinforcement.
 12. Apparatusaccording to claim 10, wherein said feeding means nozzle comprises aventuri nozzle.
 13. Apparatus according to claim 10, wherein saidfeeding means comprise a plurality of nozzles spaced laterally from oneanother and discharging into respective orifices discharging into saidslurry stream at a plurality of points to feed individual filaments intothe stream.
 14. Apparatus according to claim 10, wherein said feedingmeans comprise a wide nozzle discharging into a complementary wideorifice to feed the filamentous reinforcement in the form of scrim intothe stream.
 15. Apparatus according to claim 10, including a header,means for supplying the fibrous stock slurry to the header, a manifoldfor receiving the slurry from the header and having said orificeproviding a passage therethrough into the headbox, said nozzle beingdirected to feed the filamentous reinforcement into said passageintermediate the length of the orifice.
 16. Apparatus according to claim10, wherein the nozzle means is arranged to convey filamentousreinforcement and a fluid carrier into the orifice.
 17. Apparatusaccording to claim 16, wherein said nozzle means has venturi geometry.18. Apparatus according to claim 17, including a header having saidorifice providing an elongated passage therein, said nozzle meansdischarging into said orifice means intermediate the length of saidpassage.
 19. Apparatus according to claim 18, including conveyor pipemeans in delivering relation to said nozzle means, a carrier fluid tankcommunicating with the pipe means and through which the filamentousreinforcement is supplied into the pipe means, and means for supplyingcarrier fluid to the tank.